Samsung Galaxy S Advance — Galaxy Note 2

I just met someone last night, she convened me that we can make free calls thro whatsapp, and there is an update lets you use that new feature, i did accept the link and i did install for that app. then she took over control my galaxy note 2, it's like i lost the touch, i can't write anything, coz i can't access the keypad anymore ! i see apps opening ! and i see like someone browsing my photos ! i did reboot, but nothing ! she/he changed skype ! FB. ! Yahoo! msn ! passwords even was sending to my whatsapp contacts messages ! all of my friends and colleagues are complaining about pics and spams from my side, but i sent nothing !!!! the thing is i can't do like restore factory settings ! any help !

Wow that's a rough tale you have. I've found this list of instructions for you online. This is what I would do. Hope it works for you.

1. Turn your device off.Note: To make sure your smartphone is turned off completely, you should remove and reinsert the battery.2. Then press and hold the Volume up key.3. While you hold down the Volume up key, press and hold the Nach Hause key.4. While both the Volume up key and the Nach Hause key are pressed and held down, press and hold the Power key.5. When the Samsung logo appears, release all the three keys.6. Use the Volume down key to scroll to wipe data/factory reset.7. When you have wipe data/factory reset highlighted, press the Power key.8. Scroll to Yesdelete all user data by pressing the Volume down key.9. Once youve highlighted Yesdelete all user data, press the Power key.10. As soon as the wipe has been completed, press the Power key -> this will enable you to select reboot system now.